Modal toolbar icon style missing

I’ve got modal, where, instead of writing “Close” on the left part of the toolbar, I want to display only an icon. I followed the ionic-conference-app template (https://github.com/driftyco/ionic-conference-app/blob/3fd0a108cc000675731a15201e8f2b4083b1fdc8/src/pages/schedule-filter/schedule-filter.html) and just replace the text with an ion-icon like following:

<ion-header>
    <ion-toolbar>
        <ion-buttons start no-shadow>
            <button ion-button (click)="close()">
                <ion-icon name="close"></ion-icon>
            </button>
        </ion-buttons>

        <ion-title>MYAPP</ion-title>
    </ion-toolbar>
</ion-header>

This works fine except that I noticed that the icon doesn’t inherit the padding and font-size attributes like a menuToggle. Meaning these css attributes are missing (in case iOS) and the icon doesn’t look great (no padding, too small):

.bar-button-menutoggle-ios ion-icon {
    padding: 0 6px;
    font-size: 2.8rem;

}

Do I miss an attribute to add to my button?